2 Answers
2

What this is telling you, is that a ReadCloser interface is composed of a Reader and a Closer functionality. It IS both. That means the ReadCloser takes on those interface definitions. They are not actually members, the way you are accessing them.

Actually its both. It can have function definitions (as members), and can compose other interfaces similar to inheritance. When a type is being checked...then the it is looked at as "has a" to see that it satisfies the interface.
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jdiSep 7 '12 at 19:48